The invention relates to a method and a device to control the power of millimeter waves for a V-band TR module and, more particularly, to a method and device to control the power of millimeter waves for a V-band TR module at a frequency in the range of 50 GHz and higher, in which the transmitting and receiving path are separated by means of two SPDT (single pole double throw) MMIC switches.
The output power, particularly in the case of mobile communication units, should be as constant as possible, specifically independently of individual characteristics of the components and units, which are produced in great quantities. At frequencies <50 GHz, variable attenuators are realized on MMICs with PIN diodes or as MESFET switches. Other power control concepts for lower frequencies are also known from the prior art. However, a V-band TR module with a controlled output power is currently not known. A variable attenuator at 60 GHz as an MMIC is also currently not obtainable on the market.
The individual adjustment of the manufactured units is very cost-intensive. It would therefore be desirable to avoid this adjustment by means of a corresponding design. Simultaneously, as few additional components as possible should be required because, on the one hand, these will again scatter individually and, on the other hand, will increase costs.
The firm United Monolithic Semiconductors S.A.S., 91401 Orsay Cedex France, offers a 50–60 GHz SPDT (=Single Pole Double Throw) switch for communication systems with the designation “CHS2190a”, which has already been used as a transmit-receive switch in transmitting-receiving modules.
It is an object of the invention to provide power control with the above-mentioned characteristics while using this switch or a corresponding switch.
According to the invention, this object is achieved by a method and device to control the power of millimeter waves for a V-band TR module at a frequency in the range of 50 GHz and higher, in which the transmitting and receiving path are separated by means of two SPDT (single pole double throw) MMIC switches. For the transmission, the first SPDT MMIC switch is used as a variable attenuator and the second SPDT MMIC switch is used as a detector for the output power. By way of an electronic control circuit, the control of the output power to a defined level is achieved.
The use of the SPDT MMIC as a variable attenuator permits the adjustment of a desired transmission power and the compensation of chip spread. It forms the core component for a power control (control element). Because of the double function of the chip, the saving of costs will be considerable.
The use of the second SPDT MMIC as a power detector also results in a saving of costs because of the double function.
On the whole, the power control for the entire TR module results in an increase of the module yield by the compensation of chip spread and temperature effects. The multiple utilization of the SPDT MMICs as a switch, a variable attenuator and a power detector results in the above-mentioned advantages.
Details of the invention are indicated in the subclaims and in the description in which an embodiment is explained by means of the drawing.